The present application relates to a power storage device which is provided with a plug outlet for electronic equipment and is capable of supplying electric power to the electronic equipment. The present application also relates to a power storage system which uses the power storage device.
When a power failure occurs at the time of, for example, disaster, users are not able to use electricity until power transmission to each home is resumed. During the power failure, dry batteries (i.e., primary batteries or secondary batteries) are used widely. However, these batteries have small capacity and therefore are able to be used only for the operation and charging of portable electronic devices.
Recently, power generation devices using energy of nature, such as photovoltaic power generation devices for homes and wind power generation devices for homes, are proposed as private electric generators. However, these power generation devices are expensive for home use and therefore are not widely used in ordinary homes. Under such conditions, a power storage device provided with a battery module having a combination of plural secondary batteries, or electronic equipment with a power storage system having a function to store electricity are proposed.
The power storage device charges the battery module in, for example, the nighttime during which electricity demand is low, or a period when the power storage device is not used, and supplies power to electronic equipment connected to the power storage device as necessary. The electronic equipment with a power storage system charges the battery module in, for example, the nighttime during which electricity demand is low, or a period when the electronic equipment with a power storage system is not used, and operates without using external supply of electricity at the time of the peak of electricity demand or at the time of a power failure.
Such a power storage device or electronic equipment with a power storage system is provided with a battery module having many secondary batteries incorporated therein and a power conversion device, such as an inverter and a converter. The power conversion device generates an especially large amount of heat and the inside of the device is likely to be exposed to high temperature. Further, since plural secondary batteries are connected, the battery module is likely to be exposed to high temperature at the time of charging. When the battery module is left in a high-temperature environment, gas may be produced inside the battery or safety is threatened due to decomposition of a separator or heat contraction. Further, abnormal heat generation may occur in the battery itself and thermal runaway of the battery may be caused. Therefore, the risk may be increased.
In order to overcome these problems, in air conditioning equipment with a power storage system of Japanese Unexamined Patent Application Publication No. 11-325546, a power converter circuit portion which generates a large amount of heat is disposed at a position higher than a storage battery including plural secondary batteries. An outside air inlet is provided at a lower portion of the device and an outlet is provided at an upper portion of the device. With this configuration, air is made to flow inside the device such that heat in the power converter circuit portion which generates a large amount of heat is efficiently released outside. The heat in the power converter circuit portion is less easily transmitted to the storage battery by an insulating member provided between the power converter circuit portion and the storage battery.
As described in Japanese Unexamined Patent Application Publication No. 2003-071775, providing a dead-air space as a heat releasing mechanism between the battery as a driving power source and a heat source, such as a control circuit board, has been proposed. In Japanese Unexamined Patent Application Publication No. 2003-071775, a housing which contains the battery is thickened on the side of the dead-air space to form a thermal insulation surface. The thermal insulation surface and the dead-air space form a double thermal insulation configuration. The other surface of the housing, which is thin, is formed as a heat sink surface.